[PATCH v3 05/28] fsnotify: new tracepoint in fsnotify()

Jeff Layton
2026-04-28T07:10:42Z

Add a tracepoint so we can see exactly how this is being called.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/notify/fsnotify.c | 5 ++++
include/trace/events/fsnotify.h | 51 +++++++++++++++++++++++++++++++++++++++++
include/trace/misc/fsnotify.h | 35 ++++++++++++++++++++++++++++
3 files changed, 91 insertions(+)

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 9995de1710e5..5448738635f6 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -14,6 +14,9 @@
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"

+#define CREATE_TRACE_POINTS
+#include <trace/events/fsnotify.h>
+
/*
* Clear all of the marks on an inode when it is being evicted from core
*/
@@ -504,6 +507,8 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
int ret = 0;
__u32 test_mask, marks_mask = 0;

+ trace_fsnotify(mask, data, data_type, dir, file_name, inode, cookie);
+
if (path)
mnt = real_mount(path->mnt);

diff --git a/include/trace/events/fsnotify.h b/include/trace/events/fsnotify.h
new file mode 100644
index 000000000000..341bbd57a39b
--- /dev/null
+++ b/include/trace/events/fsnotify.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsnotify
+
+#if !defined(_TRACE_FSNOTIFY_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSNOTIFY_H
+
+#include <linux/tracepoint.h>
+
+#include <trace/misc/fsnotify.h>
+
+TRACE_EVENT(fsnotify,
+ TP_PROTO(__u32 mask, const void *data, int data_type,
+ struct inode *dir, const struct qstr *file_name,
+ struct inode *inode, u32 cookie),
+
+ TP_ARGS(mask, data, data_type, dir, file_name, inode, cookie),
+
+ TP_STRUCT__entry(
+ __field(__u32, mask)
+ __field(unsigned long, dir_ino)
+ __field(unsigned long, ino)
+ __field(dev_t, s_dev)
+ __field(int, data_type)
+ __field(u32, cookie)
+ __string(file_name, file_name ? (const char *)file_name->name : "")
+ ),
+
+ TP_fast_assign(
+ __entry->mask = mask;
+ __entry->dir_ino = dir ? dir->i_ino : 0;
+ __entry->ino = inode ? inode->i_ino : 0;
+ __entry->s_dev = dir ? dir->i_sb->s_dev :
+ inode ? inode->i_sb->s_dev : 0;
+ __entry->data_type = data_type;
+ __entry->cookie = cookie;
+ __assign_str(file_name);
+ ),
+
+ TP_printk("dev=%d:%d dir=%lu ino=%lu data_type=%d cookie=0x%x mask=0x%x %s name=%s",
+ MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+ __entry->dir_ino, __entry->ino,
+ __entry->data_type, __entry->cookie,
+ __entry->mask, show_fsnotify_mask(__entry->mask),
+ __get_str(file_name))
+);
+
+#endif /* _TRACE_FSNOTIFY_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/include/trace/misc/fsnotify.h b/include/trace/misc/fsnotify.h
new file mode 100644
index 000000000000..a201e1bd6d8c
--- /dev/null
+++ b/include/trace/misc/fsnotify.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Display helpers for fsnotify events
+ */
+
+#include <linux/fsnotify_backend.h>
+
+#define show_fsnotify_mask(mask) \
+ __print_flags(mask, "|", \
+ { FS_ACCESS, "ACCESS" }, \
+ { FS_MODIFY, "MODIFY" }, \
+ { FS_ATTRIB, "ATTRIB" }, \
+ { FS_CLOSE_WRITE, "CLOSE_WRITE" }, \
+ { FS_CLOSE_NOWRITE, "CLOSE_NOWRITE" }, \
+ { FS_OPEN, "OPEN" }, \
+ { FS_MOVED_FROM, "MOVED_FROM" }, \
+ { FS_MOVED_TO, "MOVED_TO" }, \
+ { FS_CREATE, "CREATE" }, \
+ { FS_DELETE, "DELETE" }, \
+ { FS_DELETE_SELF, "DELETE_SELF" }, \
+ { FS_MOVE_SELF, "MOVE_SELF" }, \
+ { FS_OPEN_EXEC, "OPEN_EXEC" }, \
+ { FS_UNMOUNT, "UNMOUNT" }, \
+ { FS_Q_OVERFLOW, "Q_OVERFLOW" }, \
+ { FS_ERROR, "ERROR" }, \
+ { FS_OPEN_PERM, "OPEN_PERM" }, \
+ { FS_ACCESS_PERM, "ACCESS_PERM" }, \
+ { FS_OPEN_EXEC_PERM, "OPEN_EXEC_PERM" }, \
+ { FS_PRE_ACCESS, "PRE_ACCESS" }, \
+ { FS_MNT_ATTACH, "MNT_ATTACH" }, \
+ { FS_MNT_DETACH, "MNT_DETACH" }, \
+ { FS_EVENT_ON_CHILD, "EVENT_ON_CHILD" }, \
+ { FS_RENAME, "RENAME" }, \
+ { FS_DN_MULTISHOT, "DN_MULTISHOT" }, \
+ { FS_ISDIR, "ISDIR" })

--
2.54.0